CVE-2024-21871
📋 TL;DR
This UEFI firmware vulnerability in certain Intel processors allows a privileged user to escalate privileges through improper input validation. Attackers with local access could gain higher system privileges than intended. This affects systems with specific Intel processors running vulnerable UEFI firmware.
💻 Affected Systems
- Intel processors with vulnerable UEFI firmware
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining kernel-level or firmware-level control, potentially persisting across reboots and OS reinstalls.
Likely Case
Privileged user gains administrative or SYSTEM-level access on affected machines, enabling lateral movement and data exfiltration.
If Mitigated
Limited impact with proper privilege separation and minimal local administrative accounts.
🎯 Exploit Status
Requires local privileged access to initiate exploitation. Firmware-level vulnerabilities typically require more sophisticated exploitation than user-space vulnerabilities.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: UEFI firmware updates provided by system manufacturers
Vendor Advisory: https://www.intel.com/content/www/us/en/security-center/advisory/intel-sa-01071.html
Restart Required: Yes
Instructions:
1. Check system manufacturer's website for BIOS/UEFI firmware updates. 2. Download appropriate firmware update for your system model. 3. Follow manufacturer's instructions to apply firmware update (typically requires bootable media or Windows/Linux update utility). 4. Reboot system to complete installation.
🔧 Temporary Workarounds
Restrict local administrative access
allLimit number of users with local administrative privileges to reduce attack surface
Enable Secure Boot
allEnsure Secure Boot is enabled to prevent unauthorized firmware/OS modifications
🧯 If You Can't Patch
- Implement strict access controls and least privilege principles for all local accounts
- Monitor for unusual privilege escalation attempts and firmware modification events
🔍 How to Verify
Check if Vulnerable:
Check system BIOS/UEFI version against manufacturer's patched versions. Use 'wmic bios get smbiosbiosversion' on Windows or 'dmidecode -t bios' on Linux.Check Version:
Windows: wmic bios get smbiosbiosversion | Linux: sudo dmidecode -t bios | grep VersionVerify Fix Applied:
Verify BIOS/UEFI version matches or exceeds patched version from manufacturer advisory. Check that firmware update completed successfully.📡 Detection & Monitoring
Log Indicators:
- BIOS/UEFI firmware modification events
- Unexpected privilege escalation from local accounts
- Failed firmware update attempts
Network Indicators:
- Not applicable - local access vulnerability
SIEM Query:
EventID=12 OR EventID=13 (System events for firmware changes on Windows) OR auth.log entries showing privilege escalation on Linux